Huilia crustulata (Ach.) Hertel
Lecidea crustulata Ach., Lich. Univ.: 176 (1810).
Thallus pale greyish-fawn or whitish, smooth, continuous or eroded or ± rimose in parts, often in small ± granular patches or ± lacking, delimited by a thin, black, marginal prothallus. Apothecia 0.2-1.2 mm diam., solitary or crowded, rounded to irregular-deformed through mutual pressure, disc plane to subconvex, black, epruinose, matt, margins entire, raised, persistent at first, excluded at maturity. Epithecium olive-black. Hymenium 100-145 µm tall. Hypothecium brown-black. Excipulum well-developed, interior partly carbonised. Ascospores ellipsoid, apices rather pointed, 16-33 × 7-13 µm. Chemistry: Stictic, norstictic, ?psoromic acids.
N: Wellington (on roadside boulders near Marton). S: Otago (Mt Pisgah, Central Otago on rocks).
Cosmopolitan